In an IR spectrum, the range of 4000-2700 cm-1 generally corresponds to which bonds?

The range of 4000-2700 cm-1 in an IR spectrum primarily corresponds to the stretching vibrations of bonds involving hydrogen. This range is particularly associated with O-H and N-H bonds.

When looking at specific functional groups, the O-H stretching absorption typically appears as a broad peak around 3200-3600 cm-1, indicating the presence of alcohols and phenols. The N-H stretching can occur within a similar range, but is usually not quite as broad.

In contrast, carbon-related stretches (C-H bonds) appear in this range but not to the extent that dominates those associated with O-H and N-H. Therefore, while hydrogen plays a critical role in the vibrational modes observed in this portion of the spectrum, it is specifically the hydrogen-bonding nature of O-H and N-H that frequently stands out.

Overall, the correct interpretation of this region relates to the presence of these two functional groups associated with hydrogen, emphasizing the importance of understanding IR spectral analysis when evaluating molecular structures.